One of the 276 girls abducted by Boko Haram from a school two years ago has escaped, sparking jubilation in her community and raising hopes the others might soon be found.

The girl, named as Amina Ali Darsha Nkeki, was found wandering with a baby on the edge of Nigeria's Sambisa Forest, one of the last strongholds of the Islamist militants, by one of the vigilante groups set up to tackle them. The Nigerian military said the girl, who is now 19, was accompanied by her Boko Haram "husband".

A photo released by Nigeria's army of the rescued Chibok schoolgirl and her baby Photo: Nigeria Military/Handout via REUTERS

Amina was said by relations to have been in good health but "traumatised" by more than two years in the captivity of the terror group, which has displaced more than two million people in the region and killed at least 20,000.

She told her rescuers that six of the 219 girls still thought to be in the hands of Boko Haram had died, and others were being held "under heavy terrorist captivity" in the vast forest 65km south of Maiduguri, the capital of Borno state which has been at the centre of the bloody eight-year insurgency.

More than 50 girls escaped in the months after the terrorist raid on their boarding school in the town of Chibok in April 2014, but Amina is the first to be freed since then.

Their plight, and the Nigerian government's lacklustre response, led to a global social media campaign, "BringBackOurGirls", which was championed by Michelle Obama and David Cameron.

The Chibok raid was one of hundreds across the region. Amnesty International estimates that at least 2,000 women and girls have been abducted since 2014, along with many more men and boys.

Some have been forced to become "wives" to the fighters while others have been brainwashed, trained to fight and turned into suicide bombers.

Amina was reunited with her widowed mother in the family's village near Chibok before both women and the baby were taken to a military camp.

Family and community figures said people rushed cheering towards the military convoy as it drove Amina into the town. The school's vice-principal was brought out to confirm the girl's identity, prompting more cheers. Aboku Gaji, the leader of Chibok's vigilante brigade, said he had recognised the young woman instantly and escorted her to her mother's home. "When we arrived at the house... I asked the mother to come and identify someone," he told the BBC. "The moment she saw her, she shouted her name: 'Amina, Amina!' She gave her the biggest hug ever, as if they were going to roll on the ground.

"The girl started comforting the mother, saying: 'Please Mum, take it easy, relax. I never thought I would ever see you again, wipe your tears. God has made it possible for us to see each other again'."

Amina's brother said he had immediately recognised his sister, who told him she had fled a military attack on the Boko Haram forest camp. "I was surprised to see her. They asked if I know her. I said I do. They asked if she knows me - she told them that I was her senior brother," Maina Ali said. "I am very happy to see her."

Esther Yakubu, a Chibok resident whose daughter is also among the missing girls, said Amina's mother had been living alone. "I can imagine how she will be feeling today: She will be in heaven," she added.

The Nigerian military confirmed that Amina had been recovered with a four-month-old daughter named Safiya and "a suspected Boko Haram terrorist, Mohammed Hayatu, who claimed to be her husband".

Groups of the abducted girls have been seen twice since they were captured. The first time was in a video released shortly after the raid, showing them looking terrified, dressed in hijabs and taking turns to read from the Koran. The second appearance was in March this year in a video said to be filmed at Christmas as "proof of life" to accompany Boko Haram's demand for a $50m ransom. In it, around 15 of the girls confirmed that they had been taken from the Chibok Government Secondary school, and claimed that they had not been mistreated.